The reduction of aerosolization produced by the flushing of toilets is desirable in order to reduce the possibility of airborne transmission of disease organisms from the toilet wastewater. In the application of McCune, U.S. Ser. No. 959,405, filed Nov. 9, 1978, and incorporated by reference herein, it is disclosed that the aerosolization of wastewater from flushing toilets can be significantly reduced by the presence of low levels (1-30 ppm) of high molecular weight poly(ethylene oxide) resins in the wastewater.
In treating toilet flush water with chemicals in order to produce desirable effects such as bowl cleaning, disinfection, deodorization, aerosol reduction etc., it is desirable that the chemicals be dispensed into the flush water automatically each time the toilet is flushed. The prior art discloses numerous devices which have been designed for this purpose. Exemplary of such devices are those disclosed in U.S. Pat. Nos. 3,831,205, issued Aug. 27, 1974 to Foley, 3,341,074 issued Sept. 12, 1967 to Pannutti, 3,504,384 issued Apr. 7, 1970 to Radley et al, 2,688,754 Sept. 14, 1954 to Willits et al. and 4,036,407, issued July 19, 1977 to Slone. Particularly desirable devices are those wherein the chemical composition is in the device in the form of a solid cake composition. In this type of device a measured amount of water enters the device during one flush cycle and remains in contact with the cake composition between flushes, thereby forming a concentrated solution of the composition which is dispensed into the flush water during the next flush. Obvious advantages of such devices are that the chemical composition can be packaged and shipped in more concentrated form than an aqueous solution of the chemicals, and the problems of liquid spillage resulting from breakage of the dispensers during shipment or handling is eliminated. Especially preferred devices for automatic dispensing of chemicals from solid cake compositions into the toilet are those described in U.S. Pat. No. 4,171,546 of Dirksing, issued Oct. 23, 1979, U.S. Pat. No. 4,208,747 of Dirksing, issued June 24, 1980, and U.S. Pat. No. 4,186,856 of Dirksing, issued Feb. 5, 1980, all of said patents being incorporated herein by reference.
It has been found that when solid cake compositions comprising high molecular weight poly(ethylene oxide) resins (i.e. molecular weights of from about 500,000 to about 7,000,000) are utilized in automatic dispensers, the resin forms a thick gel when exposed to the limited volume of water within the dispenser, thereby retarding or even completely blocking the subsequent flow of dissolved materials out of the dispenser and into the flush water.
It is an object of the present invention to provide solid cake compositions comprising poly(ethylene oxide)resins, which compositions are suitable for use in dispensers for automatically dispensing chemicals into the toilet.
It is a further object of the present invention to provide solid cake compositions comprising poly(ethylene oxide) resins which compositions have a reduced tendency to form gels when exposed to water.